Case-hardening compound



Patented May 27, 1924.

UNETED STATEg earner as.

EMIL SCHLEI-IAI-IN, 0F ARDMORE, ILLINOIS.

GASE-HARDENING COMPOUND.

No Drawing.

whereby to the iron or steel a case is imparted of the desired thicknesswhen the mass is placed in a furnace under a certain pro-determinedtemperature for a considerable period of time.

An. object of the invention is to reduce said time necessary forproducing the case so that by way of example a thickness of threesixty-fourths of an inch may be obtained when the necessary temperatureis maintained for three quarters of an hour.

It is also an object of the invention to provide a compound whichrenders it unnecessary to cover up the receptacle in which the articlesto be hardened are placed prior to being exposed to heat in a furnace.

\Vith these and other objects in view, the invention comprises certainingredients hereinafter further described, and more particularly pointedout in the claims.

According to the present invention, leathercharcoal, kainite, ammoniumchloride and potassium carbonate are reduced to .powdered form. Areceptacle suitable for introduction into a furnace to be exposed toheat therein is filled with the powder and the article is placed in thereceptacle to be surrounded by the powder. der is introduced into thereceptacle so that Sufficient pow- Application filed January 10, 1923.Serial No. 611,851.

approximately a layer of three quarters of an inch surrounds thearticle. The heat maintained in the furnace is approximately betweenfifteen hundredand sixteen hundred degrees Fahrenheit, and this heat ismaintained for a period of three quarters of an hour, whereupon a caseis produced having a thickness of three sixty-fourths of an inch.

A specific example of the ingredients employed is as follows:

Parts by 5 Weight.

Leather charcoal 2 Potassium carbonate M 3 Ammonium chloride 1 Kainite 1The articles hardened with a novel casehardeningcompound meet everyrequirement as to strength and hardness. If, of course, heating iscontinued for a longer period than three quarters of an hour the (athickness of the case may be increased.

In the foregoing, specific ingredients have been referred to by Way ofexplanation and not by way of limitation. It is, of course, understoodthat equivalent ingredients may be employed and I, therefore, do notdesire to limit myself except as the state of art renders thisnecessary.

I claim:

1. A case-hardening compound including leather charcoal, potassiumcarbonate, ammonium chloride and magnesium sulphate.

2. A case-hardening compound including leather charcoal, potassiumcarbonate, ammonium chloride and kainitc.

3. A case-hardening compound including two parts by weight of leathercharcoal, three parts by weight of potassium carbonate, one part byweightof ammonium chloride, and one part by weight of kainite.

In witness whereof I afiix my signature.

EMIL SGHLEHAHN.

